Abstract: 25 2nd graders' (12 males, 13 females) and 24 5th graders' (10 males,
14 females) playground activities during school recess were studied with a
1-yr follow-up. At the 2nd time of assessment, measures were also taken of
logical reasoning, interpersonal understanding, and understanding game
rules. Both grade and gender differences were found in the complexity of
Subjects' activities. Generally, older Subjects participated in more
complex activities than younger Subjects, and boys participated in more
complex activities than girls. The complexity of children's activitiesincreased over
the 1-yr period, especially for boys. The correlates of
game complexity differed for boys and girls. For boys, game complexity was
negatively related to interpersonal understanding and positively related
to understanding game rules. For girls, game complexity was positively
related to interpersonal understanding